lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* Single precision version of nexttoward.c. |
| 2 | Conversion to IEEE single float by Jakub Jelinek, jj@ultra.linux.cz. */ |
| 3 | /* |
| 4 | * ==================================================== |
| 5 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| 6 | * |
| 7 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
| 8 | * Permission to use, copy, modify, and distribute this |
| 9 | * software is freely granted, provided that this notice |
| 10 | * is preserved. |
| 11 | * ==================================================== |
| 12 | */ |
| 13 | |
| 14 | /* IEEE functions |
| 15 | * nexttowardf(x,y) |
| 16 | * return the next machine floating-point number of x in the |
| 17 | * direction toward y. |
| 18 | * This is for machines which use the same binary type for double and |
| 19 | * long double. |
| 20 | * Special cases: |
| 21 | */ |
| 22 | |
| 23 | #include <math.h> |
| 24 | #include <math_private.h> |
| 25 | #include <float.h> |
| 26 | |
| 27 | float __nexttowardf(float x, long double y) |
| 28 | { |
| 29 | int32_t hx,hy,ix,iy; |
| 30 | u_int32_t ly; |
| 31 | |
| 32 | GET_FLOAT_WORD(hx,x); |
| 33 | EXTRACT_WORDS(hy,ly,y); |
| 34 | ix = hx&0x7fffffff; /* |x| */ |
| 35 | iy = hy&0x7fffffff; /* |y| */ |
| 36 | |
| 37 | if((ix>0x7f800000) || /* x is nan */ |
| 38 | ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0)) /* y is nan */ |
| 39 | return x+y; |
| 40 | if((long double) x==y) return y; /* x=y, return y */ |
| 41 | if(ix==0) { /* x == 0 */ |
| 42 | float u; |
| 43 | SET_FLOAT_WORD(x,(u_int32_t)(hy&0x80000000)|1);/* return +-minsub*/ |
| 44 | u = math_opt_barrier (x); |
| 45 | u = u * u; |
| 46 | math_force_eval (u); /* raise underflow flag */ |
| 47 | return x; |
| 48 | } |
| 49 | if(hx>=0) { /* x > 0 */ |
| 50 | if(x > y) /* x -= ulp */ |
| 51 | hx -= 1; |
| 52 | else /* x < y, x += ulp */ |
| 53 | hx += 1; |
| 54 | } else { /* x < 0 */ |
| 55 | if(x < y) /* x -= ulp */ |
| 56 | hx -= 1; |
| 57 | else /* x > y, x += ulp */ |
| 58 | hx += 1; |
| 59 | } |
| 60 | hy = hx&0x7f800000; |
| 61 | if(hy>=0x7f800000) { |
| 62 | x = x+x; /* overflow */ |
| 63 | if (FLT_EVAL_METHOD != 0) |
| 64 | /* Force conversion to float. */ |
| 65 | asm ("" : "+m"(x)); |
| 66 | return x; |
| 67 | } |
| 68 | if(hy<0x00800000) { |
| 69 | float u = x*x; /* underflow */ |
| 70 | math_force_eval (u); /* raise underflow flag */ |
| 71 | } |
| 72 | SET_FLOAT_WORD(x,hx); |
| 73 | return x; |
| 74 | } |
| 75 | weak_alias (__nexttowardf, nexttowardf) |